textproduct: Rapid City

KEY MESSAGES

- Another round of rain, with snow in Black Hills, is likely later tonight into Monday.

- Much colder to start the week but warmer temps return by late week.

- Low-end chances for rain return later this week.

DISCUSSION

(This Evening Through Sunday) Issued at 200 PM MDT Sun May 17 2026

A change in the weather pattern is ongoing for NE WY and W SD. Cooler air has been sliding southeast into the area today. It was able to get some showers and thunderstorms going earlier in the day but now that the cold front has completely pushed through the CWA, chances for severe weather have diminished. Other impacts from this cooler air has been the much cooler afternoon temps in the 40s to 50s and we won't get much warmer than that. Also, wind gusts increased as the front pushed through with wind gust reports upwards of 35 to 40 mph.

For tonight, temps will continue to cool to well below-normal, to the upper 20s to 30s. Coldest temps will be found in NE WY where a Freeze Warning has been issued. This will most likely be repeated and expanded Monday night. Winds will remain a little elevated through tonight and tomorrow, at around 5 to 15 mph before diminishing Monday night.

As far as precip goes for tomorrow, an upper level disturbance will quickly move through, keeping widespread passing precip chances in the area. Through Monday night, total QPF amounts are up to .25 inches, highest amounts in the SD plains.

Because we are much cooler behind the cold front, we are looking at a taste of winter-like weather. For starters, some of the precip will likely fall as snow in the higher elevations of the Black Hills. At this times, upwards of 2 to 6 inches of snow is possible. A big question is - will it accumulate or will it melt as it hits the ground? Either way, a slushy, wet snow is likely late tonight into Monday.

Temperatures are still expected to be well below normal for mid- to-late May. Monday's temps look to struggle to warm up before falling for Monday night. But the cooler temps won't last long as highs in the 50s are likely Tuesday with a warming trend expected for the rest of the week.

AVIATION

(For the 00Z TAFS Through 00Z Monday Evening) Issued At 523 PM MDT Sun May 17 2026

Leftover showers with local MVFR conditions over south-central SD will wane this evening. VFR conditions over northeastern WY/western SD will change after 18/06z as an area of rain (snow up high) develops leading to widespread IFR/MVFR conditions after 18/12z across the entire area.

UNR WATCHES/WARNINGS/ADVISORIES

SD...WY...Freeze Warning from 5 AM to 10 AM MDT Monday for WYZ054>056- 058>060.